1. Field of the Invention
The present invention relates to a sheet feeding apparatus for separating and feeding sheets one by one, and more particularly, it relates to a drive mechanism for such a sheet feeding apparatus.
2. Related Background Art
In some conventional sheet feeding apparatuses, when sheets were stacked on a sheet support means, a sheet urging means for biasing the sheets upwardly was automatically separated from a sheet supply means to facilitate the stacking of the sheet, and when the stacked sheets were separated and fed, the urging means was automatically urged against the sheet supply means.
In the sheet feeding apparatus of this type, even when the sheet supply means and a switching means for switching the urging means between the separated condition and the urged condition (with respect to the sheet supply means) were driven either by respective drive sources or by a common drive source, the apparatus included a driving force switching means, such as a solenoid or wedge, for switching the transmission of a driving force to the sheet supply means or to the switching means, and/or a sensor for detecting a condition of the switching means.
However, in the above-mentioned conventional apparatus, there arose a problem in that it was made expensive when the respective drive sources were prepared for the sheet supply means and the switching means, respectively. In addition, when the sheet supply means and the switching means were driven by the common drive source, it was necessary to provide the driving force switching means for distributing the driving force or the sensor for detecting the condition of the switching means, thus making the apparatus expensive.